There’s more to be gained than just the eye health benefits when kids spend time outdoors. This blog will explain why and how from the visual development perspective. The other side of the childhood visual environment is indoors – managing close up reading, near work and screen time – which you can read about in that link.
There are three key rules for the childhood visual environment – outdoors which are important for both reducing the risk of a child becoming myopic (short-sighted) as well as reducing the risk of fast progression, or worsening, once a child is myopic.
- Spend at least 90 minutes a day outdoors
- Don’t forget sun protection – hats, sunglasses and shade
- Be physically active for least 60 minutes a day
Research has shown (link) that spending time outdoors can help protect children from becoming myopic. Once a child is myopic, it may not be as much of a strong factor in controlling the worsening – we need specific spectacles, contact lenses or atropine eye drops to do that – but it sure does help as a healthy habit. Busy lives and full schedules can mean that outdoor time, and play in general, gets relegated lower down the priority list.
Aside from the vision benefits, though, there are numerous physical and psychological benefits to children getting outdoors and especially into nature. Shockingly, a 2016 survey (link) found that three quarters of UK children spent less time outdoors than prison inmates, with 20% never playing outdoors on a regular basis.
Bright light, play time, sun time
We are still learning what the ‘magic sauce’ is with outdoor time. It doesn’t appear to be that the child is simply not reading, as the Sydney Myopia Study (link) showed that children can spend a lot of time reading and still get a lot of outdoor time. It doesn’t appear to be physical activity – a Brisbane-based study (link) showed that children who became myopic weren’t less physically active than the children whose vision stayed clear, they just simply got less exposure to bright light. Perhaps they were doing more indoor sports. That being said, it is very important for children to be physically active, for at least 60 minutes a day, as per the recommendations of the Australian Government Department of Health and the American Academy of Pediatrics.
The ‘magic sauce’ might instead be the brightness of outdoor light. Even on a cloudy day outdoors, and even with super bright artificial lighting indoors, outdoor light is many magnitudes brighter. This may be stimulating the young eye to grow at the correct rate, via a neurotransmitter in the eye and the brain called dopamine, and not at the accelerated rate as is the case in childhood myopia. It might also be about the process of looking far away, and having the whole of the retina (the light sensitive film at the back of the eye) stimulated in a more equivalent way, compared to when we’re indoors and looking up close, where we tend to use our central vision much more so.
Sun protection is still very important. Research from Singapore has shown that if a child is outdoors, in the shade, with a hat and sunglasses on – the brightness of the light at the eye level is still at least several times brighter than indoors next to a large window. Our sun protection mantra in sun-drenched Australia – slip on a shirt, slop on sunscreen, slap on a hat, slide on sunglasses and seek the shade! What about countries with less sunlight, you might wonder?
Fascinating research from Norway (link) has shown that even with their dark winters, Norwegian children have a much lower rate of myopia than children in the UK, or USA, or even Australia – while genetics will play a part, this could be due to their culture of sending their children outdoors – rugged up as much as needed – rain, hail or shine every day!
Indoor light and new technology
In China, where the prevalence of childhood myopia is at 80%-90%, there are schools experimenting with glass-walled ‘Bright Classrooms’ to simulate outdoor lighting conditions inside where the students spend most of their days. We are still learning about whether different types of indoor lighting could influence eye growth in children (it’s been shown to be the case in animal research models) so for now, maximizing natural lighting and increasing outdoor time is the best action to take.
New smartwatch technology (link) is being developed to help encourage children to spend more time outdoors, by monitoring the brightness of the light exposure to a smartwatch worn by the child. In future perhaps we’ll be adding this to our toolkit to manage childhood myopia, along with special smartphone and screen apps to manage reading distance and of course the now ubiquitous physical activity trackers.
What can you do?
- Children of all ages should spend at least 90 minutes a day outdoors. While this can seem hard to achieve in our busy lives, it may be mostly achieved at school for primary-school aged children. Talk to your child’s teacher about their break time activities if you’re unsure. On the weekend, plan a family outing – even a walk to the local park and a short play will help the minutes tick away.
- Moderate to vigorous physical activity for at least 60 minutes a day is recommended for school aged children. If this is spent outdoors, all the better for their visual development. Again, for primary school aged children, this may be mostly achieved in break times.
- Be sun smart with outdoor time – hats, sunglasses and shade – and your child will still get the eye health benefits.